Without the change in `src/graph.cc`, this test fails like:

    hummer:ninja thakis$ ./ninja_test 
    [54/164] BuildWithDepsLogTest.RestatDepfileDependency
    *** Failure in src/build_test.cc:1659
    Value of: builder.Build(&err)
      Actual: false
    Expected: true
    *** Failure in src/build_test.cc:1660
    Value of: err
      Actual: "stuck [this is a bug]"
    Expected: ""
    [80/164] DepsLogTest.RecompactRecompacting deps...
    [164/164] ElideMiddle.ElideInTheMiddle
    failed